SUMMARY OF THE INVENTION
The invention is directed to an improved landscape fabric which permits the flow of air and water while resisting the passage of light therethrough.
Landscape fabric is commonly used today in landscaped areas for resisting the growth of weeds and other unwanted plant life. Conventional landscape fabric consists of an opaque film of polyethylene, typically black, having a thickness of 3-6 mils. The film is typically sold in long rolls that are typically 3 feet in width.
After the landscaped bed is prepared with proper soil and drainage, the landscape fabric is unrolled, placed over the bed and cut to any curved configuration of the bed. It is typically staked in place with plastic or steel staples or spikes to prevent movement. Holes are then cut in the fabric at points where plants are desired, and the plants (e.g., trees, bushes and perennials) are then planted through the fabric openings or holes and into the soil. The fabric is then covered by several inches of wood mulch, gravel or rocks, and in the case of crops such as strawberries or tomatoes, tucked into the sides of the plant bed.
Because the landscape fabric is imperforate, water and air are prevented from passing therethrough except through the holes cut as plant openings. Its opaqueness prevents the transmission of light. These water, air and light blocking functions substantially prevent the germination and growing of weeds, which is the primary function of the fabric. However, conventional landscape fabric is not without disadvantages.
First, because it is imperforate other than the plant openings, water and air for the growth of the desired plant life is itself restricted. This can be overcome to some extent by cutting relatively large openings for the plants, but in so doing the germination and growth of weeds is also encouraged in this enlarged area.
Second, conventional landscape fabric is flat and relatively thick, and although flexible to some extent it does not conform well to the irregular contours of the ground. It is possible to cause a tear or hole in the fabric if excessively stressed in a particular area, which can lead to weed growth. However, more importantly, the inability of the landscape fabric to stretch and/or conform to the contours of the ground make it more difficult to install.
The inventive landscape fabric overcomes these problems through its unique design.
Broadly speaking, the landscape fabric is formed (preferably by rotary molding) to include a plurality of ridges each of which has at least one upstanding or substantially vertical wall. In the preferred embodiment, the improved landscape fabric is formed with a plurality of aligned or parallel ridges and alternating valleys, with each ridge consisting of two substantially vertical walls and a rounded top. Small apertures are formed in each vertical wall which permits the flow of both water and air to the underside of the fabric. This flow is enhanced by the formation of a plurality of small transverse channels disposed in the trough or valley between the ridges in alignment with the apertures. Preferably, the transverse channels extend between opposed apertures in adjacent ridges. As water moves through the troughs or valleys between ridges, it falls into the small transverse channels and is led to the apertures, thus flowing through the fabric to ensure that the soil below the fabric is moistened with rain or watering.
However, at the same time, the fact that the apertures are disposed in substantially vertical walls inhibits the passage of light, which cannot travel horizontally in the troughs or valleys to reach the apertures.
The desired plants themselves receive adequate sunlight because they project through and above the landscape fabric. However, weeds and undesired plant life cannot gain a foothold below the fabric because they are unable to receive the necessary sunlight to grow.
The formation of the improved landscape fabric with a significant number of aligned ridges alternating with valleys is also advantageous because it gives the fabric some degree of stretch, thus enabling it to better conform to the contours of the land and any irregularities it may contain. Thus, it is more easily installed than conventional landscape fabric.
The improved landscape fabric is preferably formed from high density polyethylene with a thickness of 5 mils. The combination of the heavy thickness of the film and stiffness of the high density polyethylene results in a landscape fabric that is flexible while having improved strength and the ability to hold its shape in the application. The use of high density polyethylene also is advantageous because it enables formation from recycled plastic. Plastic milk bottles provide a readily available source of high density polyethylene, the reuse of which results in a highly useful product that simplifies installation and provides better long range results in plant growth and weed inhibition.